Johnson, 33, must pass a physical before the agreement can be finalized.
This will be Johnson's third stint with the Braves. He made his major league debut with Atlanta in 2005, then signed with Arizona before the 2010 season. He also played with Toronto, Tampa Bay, the Yankees, Baltimore and Boston before returning to the Braves in 2015. He hit .275 with nine homers with Atlanta last season, then was traded to the Mets on July 24.
Johnson is expected to share time with third baseman Adonis Garcia and also play other infield positions and left field.
The Associated Press contributed to this report.